COURTESY PHOTO | U.S. Geological Survey map showing the location of Tuesday's earthquake beneath the ocean floor south of Southampton

Feel something shaking Tuesday morning? It was an earthquake registering 3.9 on the Richter Scale deep under the ocean floor south of Southampton.

The quake struck at 10:45 a.m. 79 miles south-southeast of Southampton more than four miles below the ocean’s surface, the Lamont-Doherty Cooperative Seismographic Network reported. Tremors were felt across the East End.

“I was reading and all of a sudden the house started to rattle,” said Jack McGreevy of Mattituck. “It felt like I was back in Brooklyn when the coal trucks used to rumble by.”

The tremors lasted no more than five seconds “but it was very noticeable,” he said. “It got my attention.”

His house was undamaged and nothing fell off his shelves.

The Riverhead and Southold police report receiving no earthquake-related calls.